Re: [patch 21/21] slab defrag: Obsolete SLAB

Matthew Wilcox
2008-05-14T21:21:44Z

On Wed, May 14, 2008 at 02:00:15PM -0700, Christoph Lameter wrote:
> On Wed, 14 May 2008, Matthew Wilcox wrote:
>
> > On Wed, May 14, 2008 at 01:46:52PM -0700, Christoph Lameter wrote:
> > > Some more on SMP scaling:
> >
> > These are all great theories, and you mentioned that you'd fixed the
> > regressions with tbench, but did you fix the regression with the io-gen
> > program I sent you?
>
> No. I thought you were satisfied with the performance increase you saw
> when pinning the process to a single processor?

Er, no. That program emulates a TPC-C run from the point of view of
doing as much IO as possible from all CPUs. Pinning the process to one
CPU would miss the point somewhat.

I seem to remember telling you that you might get more realistic
performance numbers by pinning the scsi_ram_0 kernel thread to a single
CPU (ie emulating an interrupt tied to one CPU rather than letting the
scheduler choose to run the thread on the 'best' CPU).

--
Intel are signing my paycheques ... these opinions are still mine
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."